أَخْبَرَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ أَيُّوبَ، عَنْ أَبِي قِلَابَةَ، قَالَ: قَالَ أَبُو مُسْلِمٍ الْخَوْلَانِيُّ: "الْعُلَمَاءُ ثَلَاثَةٌ: فَرَجُلٌ عَاشَ فِي عِلْمِهِ وَعَاشَ مَعَهُ النَّاسُ فِيهِ، وَرَجُلٌ عَاشَ فِي عِلْمِهِ وَلَمْ يَعِشْ مَعَهُ فِيهِ أَحَدٌ، وَرَجُلٌ عَاشَ النَّاسُ فِي عِلْمِهِ وَكَانَ وَبَالًا عَلَيْهِ".
Abu Muslim Khawlani, may Allah have mercy on him, said: There are three types of scholars. One is the person who lives by knowledge and others also live with him in knowledge. The second is the person who himself remains in the world of knowledge but no one else is with him. The third is the person from whose knowledge people benefit, but (he himself does not act upon it); knowledge will be a burden upon him.